Pump



April 16, 1935. B. GROB ET AL 1,998,083

PUMP

Filed Nov. 11, 1933 a I 4/ n1 ji/flgalv 4/ W0 20 59' 1" 40 ,7 4 g 32 35 /4 /9 3 t i i /8 IN VENTOR.

ATTORNEYS Patented Apr. 16, 1935 PATENT OFFICE PUMP Benjamin Grob and Theodore Grub, West Allis, Wis.

,-Application November 11, 193? Serial No. 697,683

6 Claims.

The present invention relates in general to improvements in the construction and operation of mechanism for converting rotary motion into reciprocating motion, and vice versa, and relates more specifically to improved motion transmission mechanism especially applicable to high speed machines such as reciprocating pumps or other similar assemblages.

An object of the invention is to provide an improved motion transmitting mechanism which is simple and compact in construction, and which is moreover highly efficient in operation.

Another object of the invention is the provision of a durable high speed machine wherein rotary motion may be quietly and effectively converted into reciprocatory motion, or vice versa.

A further object or" the invention is to provide various improvements especially applicable to air pumps or the like, whereby the various parts of such structures are made conveniently accessible for adjustment, inspection and renewal of parts.

' of constructing and of operating air pumps built in accordance with the invention, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views:

Fig. 1 is a central vertical section through a high speed air pump, taken transversely through the main driving shaft thereof;

Fig. 2 is a longitudinal vertical section through a portion of the air pump of Fig. 1;

Fig. 3 is an enlarged horizontal section through the discharge valve chamber of the pump, taken along the line 3-3 of Fig. 1; and

Fig. 4 is a central vertical section through a fragment of a modified pump structure. 7

While the invention is shown and described herein as being specifically applied by way of illustration, to air pumps of the reciprocating piston type, it is not intended to unnecessarily restrict the scope by such disclosure, since at least some of the features of the improvement may be more generally applicable to other classes of machines such as positive displacement reciprocating piston engines.

Referring to Figs. 1 to 3 inclusive of the drawing, the air compressor specifically shown therein comprises in general a main casing 6 having a removable end cover 1; a shaft 8 rotatably supported in a pair of concentric anti-friction bearings ii, iii mounted in the casing 6 and cover 1 respectively; an eccentric II carried by the shaft 3 between the bearings 9, It]; a relatively large anti-friction bearing I2 embracing the eccentric H and having an outer race or ring member i3, an auxiliary casing M removably attached to the main casing and projecting upwardly therefrom; a cylinder i5 detachably connected to the upper end of the auxiliary casing l4; a piston l6 reciprocable within the cylinder i5; a piston rod ll secured at its upper end to the piston It and slidable at its lower portion in a guide bearing i8 mounted in the casing 14; and a spring IQ for constantly urging the lower extremity of the rod IT in contact with the bearing member l3.

The shaft fimay be detachably connected to an electric motor or other source of rotary motion, by means of an ordinary flexible coupling associated with the protruding shaft end, and a flange so is rigidly attached to or formed integral with the shaft at this end and coacts directly with the inner revolving race of the ball bearing 9. The portion of the shaft 3 which is normally 'consealed within the casing t and cover I, is devoid of key-ways, and the concealed end of the shaft is threaded and has a clamping nut 2i coacting therewith. Embracing the shaft 8 at each side of the eccentric i i, is a balancing or counter-weight 22 for the eccentric, and each of these weights 22 may be composed of several layers of sheet metal having like or different gauge selected to insure perfect counter-balancing. The counterweights 22 are rigidly attached to the eccentric l I by a rivet 23, and the inner race of the ball-bearing i2 is clamped to the eccentric by collars 24 interposed between the ends of the eccentric and the adjacent weights 22, these collars 24 also being penetrated by the rivets 23 as shown in Fig. 2. In order to insure such clamping of the inner bearing race, the eccentric I I may be formed of slightly less width than the race, and the rigidly interconnected eccentric H, weights '22 and collars 24 are all bored to snugly fitthe shaft 8. The outer faces of the counter-weights 22 are engaged by collars 25, 2t snugly embracing the shaft H, and these collars 25, 26 have end engagement with the inner races of the bearings 9, i K respectively, so that when the nut 21 is driven home against the adjacent lock washer, the eccentric ll, bearings 9, l0, counter-weights 22 and collars 2 25, 26 are all simultaneously locked in position upon the shaft 8 and against the fixed flange 28. The cover '5 which is detachably connected to the casing 6 by cap screws 27, obviously permits such assembly of the elements upon the shaft H, and removal thereof, and the interior of the casing E is normally supplied with a bath of lubricant. It should also be noted, that the outer race of the anti-friction bearing 9 is confined within an end bore in the casing S by a plate 2!} and cap screws 29, while the outer race of the other shaft bearing 58 is slidably mounted in a bore 30 of the cap I so as to permit free endwise removal of this cap.

The auxiliary or guide casing M is rigidly but removably connected to the main casing 6, by means of cap screws 3!, and the cylinder 15 of Figs. 1, 2 and 3, is fitted. within a bore formed in the longitudinally split upper end of the casing l4 and may be clamped firmly therein by means of a clamping bolt 32. While the cylinder I5 is susceptible of slight vertical adjustment, the lower end of this cylinder would ordinarily rest upon a transverse plate 33 which is mounted within the casing l4 and provides an upper guide for the rod H as well as a limit stop for the cylinder. The wall of the cylinder 25 is pierced by a series of suction ports 3 disposed above the upper extremity of the guide casing I4, and these ports may be surrounded by a suction casing 35 having a hose attaching nipple 35 and a clamping screw 37 as shown in Fig. The upper end of the displacement chamber of the cylinder has therein a central discharge port 38 controlled by a hexagonal discharge valve 35 normally pressed to its seat by means of a spring 5B the upper end of which reacts against a removable plug 4! having a discharge hose attaching nipple formed integral therewith. The dischar e valve 39 is formed hexagonal as shown in Fig. 3, or of some other polygonal cross-section, in order to permit free escape of the fluid being pumped, and the plug 4! permits free insertion, inspection, or removal of this valve.

The piston H5 is detachably connected to the upper end of the rod IT, and has a cup-leather or other suitable packing 42 held in place by a fol-- lower plate 43 as shown in Fig. l. The lower portion of the rod I? which slides within the guide bearing I8, is of enlarged diameter so as to permit the spring l9 which embraces the thin rod portion and which is of approximately the same external diameter as the thick. rod portion, to be inserted and removed with the piston rod through the bore of the bearing l8. The upper end of the spring I9 reacts against the plate 33, while the lower end engages the rod shoulder, and the lower extremity of the rod 51 is enlarged for extended contact with the peripheral surface of the outer race or ring member iii of the eccentric bearing l2. The casings 6, l4 may be provided with one or more lubricant drainage holes 44 for returning oil escaping past the guide bearing #8 to the main casing E, and it is to be noted that by removing the casing M from the casing G, and utilizing the lower enlarged end of the piston rod H to unscrew this rod from the piston N3, the rod ll and spring is may be withdrawn through the guide bearing It. This guide bearing may also be inserted or removed from the casing 14 from the exterior thereof when removed from the casing 6.

During normal operation of the improved compressor, the shaft 8 is being rotated at relatively high speed within the ball bearings 9, 23, thereby causing the eccentric H and counter-weights 22 to revolve within the casing t and to splash the lubricant from the bath in the bottom of the casing upon the bearings 9, l0, H and I8. The concealed elements are thus abundantly lubricated and any oil which escapes into the interior of the casing M will be returned through the holes 64 to the interior of the casing 6. As the eccentric H and the anti-friction bearing 22 associated therewith, revolve, the ring member l3 of the ball bearing engages the enlarged end of the piston rod H and moves this rod longitudinally to thereby cause the piston 16 to approach the discharge port 3d. The spring 59 functions to move the rod I! in opposition to the motion imparted thereto by tlie.eccentric, thus causing the piston I S to reciprocate and to constantly coact with the ring member 13 of the large eccentric ball bearing. The receding movement of the piston I6 is sufiicient to cause the piston in its downward motion to uncover the suction ports 34, and when this is done, air is withdrawn through these ports into the displacement chamber of the cylinder l5 and this air after being compressed is delivered through the discharge port 38 past the discharge valve 39. As the reciprocation of the piston 15 and rod '1 is continued by the constant revolution of the eccentric ii and bearing H, a substantially constant stream of compressed air is discharged through the plug 4! and this air may be delivered to storage tank and subsequently utilized as desired. By virtue of the fact that the ring member I3 is rotatable with respect to the balls and inner race of the bearing !2, the sliding action between the member [3 and the rod l! is reduced to a minimum. The counterweights 2?. effectively counter-balance the eccentric I3 and the collars 24, thereby reducing the vibration and the noise to a minimum, while effectively converting the rotary motion of the shaft 8 into reciprocatory motion of the rod 11.

In the modified construction specifically illustrated in Fig. 4, the construction of the piston l6, discharge valve 39 and plug is substantially the same as that previously described. The mode of attaching the cylinder l5 to the auxiliary casing I4, is, however, different. In this modification the external surface of the cylinder l5 is provided with screw threads 45 and the cylinder has screw thread coaction with the upper extremity of the casing l4 which is not split as in the pump of Figs. 1 and 2. The discharge casing 35' also has screw thread coaction with the err-- ternal threads 45 of the cylinder 15, and this casing 35 serves as a lock nut to clamp the cylinder 15' in adjusted position relative to the casing 14. The suction ports 3% of the cylinder I5 are formed of greater length than in the pump previously described, so as to take care of the adjustment of the cylinder, and the casing 35 will provide fixed upper limits for the suction openings. With this modified construction, it will be apparent that the cylinder l 5 may be adjusts vertically to vary the volume of the compression chamber, and if so desired, such adjustment can be utilized to vary the degree of compression. If the compression chamber is enlarged, lower discharge pressure will be attained than if this chamber is reduced to a minimum, and such adjustment may be desirable in connection with certain classes of service.

From the foregoing description it will be apparent that the invention provides a simple, compact, durable and highly efficient mechanism for converting rotary into reciprocatory motion, and vice versa. All portions of the structure are readily accessible for assembly, inspection or dismantling, and the clamping nut 2| and flange 20 serve as simple and highly effective means for attaching the eccentric I! and the counter-weights 22 to the shaft 8, without the use of keys or set screws. These elements are, however, readily accessible upon removal of the cap I, and the piston I6 and rod I! are likewise readily accessible by virtue of the removability of the cylinder and of the auxiliary guide casing. The device may be operated at comparatively high speed with minimum vibration and noise, and has proven highly successful in commercial operation for air compressing purposes. The noise and vibration are obviously minimized by mounting the anti-friction hearing I 2 directly upon the eccentric and by counterbalancing the weight of this bearing as well as that of the eccentric with the counterweights 22, and the additional anti-friction bearings 9, I!) assure smooth running of the unit which is abundantly lubricated by the splash system. While the modification of Fig. 4 provides for vertical adjustment of the cylinder, with the aid of screw threads, it will be apparent that such adjustment is also possible with the construction specifically shown in Figs. 1 and 2.

It should be understood that it is not desired to limit the invention to the exact details of construction herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In combination, a main casing, a horizontal rotary shaft having an eccentric portion provided with an annular surface disposed within said casing, a ring member surrounding and spaced from said surface within said casing, a series of rollable elements interposed between said member and said surface, an upright rod having an enlarged lower end contacting with the periphery of said member within said casing, said casing having an upper opening through which said rod end is removable, a guide casing removably attached to said main casing and having a lower rod guiding portion normally closing said opening, a transverse plate carried by said guide casing and having an upper rod guiding portion disposed within said casing, a spring coacting with said plate and with said rod to urge said rod end in contact with said member, a cylinder carried by said guide casing above said plate, and a piston secured to the upper portion of said rod and reciprocable within said cylinder.

2. In combination, a main casing, a shaft supporting eccentric mechanism for revolution within said casing, an upright rod having an enlarged lower end contacting with said mechanism within said casing, said casing having an upper opening through which said rod end is removable, a guide casing removably attached to said main casing and having a lower rod guiding portion normally filling and closing said opening, a transverse plate attached to said guide casing and having an upper rod guiding portion disposed within said casing in alinement with said lower rod guiding portion, a spring confined within said guide casing below said plate and coacting with said rod to urge said rod end in contact with said mechanism, a cylinder detachably connected to said guide casing above said plate, and a piston detachably secured to said rod above said plate and reciprocable within said cylinder.

3. In combination, a main casing, a shaft supporting eccentric mechanism for revolution within said casing, a vertically movable rod having an enlarged lower end coacting with said mechanism within said casing, said casing having an upper opening through which said rod end is removable and also having a side opening through which said mechanism is removable from within said casing and from said shaft, a detachable cap forming a closure for said side opening and providing a bearing exposed only to the interior of said casing for supporting the end of said shaft, a guide casing removably attached to the top of said main casing and having a lower rod guiding portion normally filling and closing said upper opening, a guide plate associated with said guide casing and having an upper rod guiding portion disposed within said casing and in vertical alinement with said lower rod guiding portion, spring means confined within said guide casing and coacting with said rod to urge the same downwardly to cause said enlarged end to contact with said mechanism, a cylinder carried by said guide casing above said upper rod guiding portion, and a piston carried by said rod. and reciprocable within said cylinder.

4. In combination, a main casing, a horizontal V rotary shaft penetrating one side of said casing and having a removable eccentric portion provided with an annular surface disposed within said casing, a ring member surrounding an spaced from said surface within said casing, a series of rollable elements interposed between said member and said surface, a vertically reciprocable rod having an enlarged lower end coacting with the periphery of said member Within said casing, said casing having an upper opening through which said rod end is removable and also having a side opening through which said eccentric, ring member, and rollable elements are removable from within said casing and from the end of said shaft, a cap forming a closure for said side opening and providing an enclosed bearing for said shaft and exposed only to the interior of said casing, a guide casing removably attached to said main casing and having alower rod guiding portion normally filling and closing said upper opening, means forming an upper rod guiding portion disposed within said casing in vertical alinement with said lower rod guiding portion, a cylinder carried by said guide casing above said means, and a piston carried by said rod above said means and reciprocable within said cylinder.

5. In combination, a main casing, a horizontal rotary shaft carrying an eccentric portion provided with an annular surface disposed within said casing, a ring member surrounding and spaced from said surface within said casing, a se-' ries of rollable elements interposed between said member and said surface, an upwardly extending rod having an enlarged lower end contacting with the periphery of said ring member within said casing, said casing having an upper opening through which said rod end is removable, a guide casing removably attached to said main casing and having a lower rod guiding portion normally closing said opening, a transverse plate disposed within said guide casing, a spring coacting with said plate and with said rod to urge said rod end in contact with said ring member, a cylinder carried by said guide casing, and a piston carried by the upper portion of said rod and reciprocable within said cylinder.

6. In combination, a main casing, a horizontal rotary shaft penetrating one side of said casing and having a removable eccentric portion provided with an annular surface disposed within said casing, a ring member surrounding and spaced from said surface within said casing, a series of rollaole elements interposed between said member and said surface, an upwardly extending reciprocable rod having an enlarged lower end coacting with the periphery of said member within said casing, said casing having an upper opening through which said rod end is removable and also having a side opening through which said eccentric, ring member, and reliable elements are removable from within said casing, a cap forming a closure for said side opening and providing a bearing for said shaft, a guide casing removably attached to said main casing and having a lower rod guiding portion normally filling and closing said upper opening, means forming an upper rod guiding portion disposed within said casing in alinement with said lower rod guiding portion, a cylinder carried by said guide casing, and a piston carried by said rod and reciprocable within said cylinder.

BENJAMIN GROB.

THEODORE GROB. 

